Reactivity in Opaline #300

Whilst I was really pleased about how the colours mixed in my cast tests I was not really over the moon with the reaction between the opaline white and black. 

This picture really doesn't show it much at all but around the black where it touches white there is a bright yellow halo thing. There doesn't seem to be any information about the reactivity of Gaffer casting crystal anywhere online- I'm probably just being a bit useless though. 

At the moment I don't think there's anything I can really do about it so for now I'm just going to have to work around it. Marble does have yellowy/creamy discolourations sometimes though so it's bad but not a complete disaster! 

Cast Marble Tests Ready

My first cast tests came out this afternoon. 

I'm pleased with the way the glass has mixed within the mould. I got a little bit worried after I had already put them in that I should have been melting the glass in through a plant pot. I knew that I didn't want them to be really swirly though but I wasn't really sure what to expect. In the end though it has all went okay. 

The two on the left (a) have 15g of grey and 1g of black, the two in the middle (b) have more grey (20g), and the two on the right (c) have more black (2g). They all have 120g of white. 

Set (a). 

Set (b). 

Set (c). 

I don't really have any preference, I don't think the amounts of colour in them help to differentiate them. If I had to chose I would say the bottom cast in the photo of set (b) is the best as the colours have mixed in a more feathery (but not swirly) way.

Test: Take One

First thing on Monday morning I opened my kiln and surprisingly I was very pleased with what met me. For a start neither of my moulds had cracked. I chose to test my strongest and weakest colour gradients and I think the difference between them is very interesting and to be honest just about what I was expecting.

5% colour. 

30% colour.

There was a couple of things that I'm not entirely happy with but I am changing a few things around for my next test- which will hopefully go in tomorrow. Firstly they have quite a lot of bubbles (this is more noticeable in the darker cast) and secondly I made my mould (from the wax) slightly wonky so the tops of them are slightly askew. 

Don't panic though, to try and reduce the bubbles I'm taking my kiln up slightly higher (from 800°C to 820°C) and holding it here for an extra hour. Hopefully this will work a bit better and I will have a clearer over all cast.